The modern Mexico Megacity occupies almost a third of the surface of the Valley of Mexico, and it is exposed to natural and man-induced hazards affecting many aspects of urban development. Land subsidence is a geo-hazard imposing important constraints in the urban development by the gradual decrease in elevation of the land surface. This is caused either naturally, by the extraction of water, oil, minerals, or gas from the subsurface, or by the interaction between natural and anthropogenic forces. In this field trip guide we examine regional land subsidence and the vulnerability to fracturing of the lacustrine soils. Groundwater has been over-exploited for human consumption in Mexico City during the past 70 years, leading to a dramatic decline of piezometric levels and the associated land and subsoil deformation. Interdisciplinary research from geologists and engineers may play an important role in understanding the relationship between geological processes and the suitability of land for urban use.

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A set of 38, 30 x 30 m resolution rasters of the subsidence over Mexico City and part of its metropolitan area, has been made available through this work. Subsidence rates in Mexico, one of the most populated cities in the world, reaches up to 0.4 m/yr, mainly due to soil compaction led by over exploitation of the Mexico Basin aquifer. To accurately map the spatial and temporal evolution of this phenomena, a set of Synthetic Aperture Radar images has been processed through interferometry and the results have been formatted as rasters that can be read and analyzed on any Geographic Information System. Moreover, the whole set of rasters can be visualized as interactive animated time series of the subsidence, through the journal platform.